P4DC6+ and Hyperthreading

I've got hyperthreading enabled in the BIOS on my P4DC6+ (dual Xeon
2.4's) and XP Professional shows 4 processors OK, but I'm not sure
things are working correctly. When I start a CPU-intensive process like
WinRAR, the first CPU in Task Manager pegs out at 100%, but just about
anything else I attempt to run seems to be waiting for CPU, even tho the
processor utilization shows only 25%. Shouldn't a new process be routed
to another CPU by the OS?

Anybody have any light to shed on this? I am thinking about disabling
hyperthreading in the BIOS. Any comments?

Thanks,
Luigi

The problem, most likely, is that WinRar is not written for multi-CPU
environments. Most applications are not. So, if you're using that type
of application (this includes MS Office, almost all games, possibly
WinRar, etc) only a single CPU will be utilized. The program running
will not even realize there are additional CPU(s) available. Try
running something like Photoshop, SQL, etc, and you'll start to see a
marked difference. Less exciting applications will just run on the one CPU.
As an aside, disk speed has nothing to do with it. If you're running
Photoshop on the oldest slowest hard drive you can find, all "4" CPUs
are going to see some action, but it's going to be lighter than if you
had a SCSI RAID array, for example...

Ed

Luigi wrote:
 > I've got hyperthreading enabled in the BIOS on my P4DC6+ (dual Xeon
 > 2.4's) and XP Professional shows 4 processors OK, but I'm not sure
 > things are working correctly. When I start a CPU-intensive process like
 > WinRAR, the first CPU in Task Manager pegs out at 100%, but just about
 > anything else I attempt to run seems to be waiting for CPU, even tho the
 > processor utilization shows only 25%. Shouldn't a new process be routed
 > to another CPU by the OS?
 >
 > Anybody have any light to shed on this? I am thinking about disabling
 > hyperthreading in the BIOS. Any comments?
 >
 > Thanks,
 > Luigi<!-- ~MESSAGE_AFTER~ -->